First Noninvasive Test For Chromosomal Defects In Unborn Babies

Researchers have revealed a new and safer method for detecting chromosomal abnormalities in developing fetuses. According to The American Journal of Human Genetics, a new study shows that the new method — which analyzes fetal DNA in the mother’s blood — could even be more informative than more traditional methods, without the risk of miscarriage.

Traditional methods of chromosomal analysis generally include chorionic villus sampling and amniocentesis, both which are invasive procedures which carry some risk to the mother and fetus in the from of infection or miscarriage.

Senior study author Richard Rava of Verinata Health notes, “Our study is the first to show that almost all the information that is available from an invasive procedure is also available noninvasively from a simple maternal blood draw.”

In the aforementioned traditional methods of chromosomal analysis, either tissue from the placenta or fluid from the amniotic sac is removed from the mother. Then, pictures of chromosomes are taken through a microscope. The pictures, called metaphase karyotypes, are analyzed, and abnormalities associated with developmental delays, intellectual disabilities, congenital defects, or autism can be detected. Recently, a chromosome microarray has been shown to provide even more detailed information, but still requires an invasive procedure.

In the first noninvasive method, massively parallel sequencing (MPS) of fetal DNA in the mother’s blood now allows for a safer alternative to detect chromosomal abnormalities. In the new study, Rava and his team found that MPS was “capable of detecting a variety of chromosomal abnormalities as accurately as chromosome microarrays.”

“Such a noninvasive test could have clinical utility in the near future, particularly for women who either have a medical contraindication or lack access to an invasive procedure,” Rava says. “This work suggests an exciting future path toward routine noninvasive detection of abnormalities in the entire fetal genome.”